Laser drilling apparatuses and methods of drilling work pieces or objects are well known in the art. For example, it is known to use lasers and associated optics to drill holes in surgical needles, medical devices, aerospace components, automotive components, electronic components, and military components. The size of the opening to be drilled in the workpiece, and the type of material will dictate the type of laser and its output. Types of lasers that can be used for drilling procedures include Nd-Yag, carbon dioxide, and ruby lasers. Power outputs of these lasers may typically be in the hundreds of watts and are a function of the materials, hole diameters, hole depths, and beam energy required to drill such holes.
When drilling a hole in a metal workpiece, it is known that the metal heated by the laser beam is melted in discrete volumetric sections as the heat from the laser beam is absorbed and conducted by the metal. The molten metal subsequently is expelled from the opening by the force of vaporized metal that is also produced by the laser beam. In order to efficiently produce an opening and a hole in a metal work piece using a laser drilling apparatus, it is typically necessary to pulse the laser beam in precise, timed segments to allow the volumes of molten metal to be expelled as each laser beam segment is applied.
Quite often, laser drilling operations are conducted in high speed manufacturing environments where the workpieces are mounted to high speed production machines, such as progressive index machines. Inherent with such operations and machinery is vibration that is transmitted through the machinery and to the workpiece. This can be problematic if the hole to be drilled in the workpiece must be precisely located and must have precise dimensions. It is known to mount lasers to the frames of high speed machinery on vibration absorbing mounts, but this typically will not eliminate all of the vibration to the laser, and the workpiece continues to vibrate. It is known that the mirrors and other components of a laser are sensitive and can become misaligned or damaged by vibration. Similarly, it is know to mount a laser remotely from the frame of the high speed machine. Although this protects the laser from vibration, it does not eliminate the problems associated with the workpiece vibrating and does not alleviate the difficulties in attempting to precisely drill a hole in the workpiece.
Therefore, there is a need in this art for a novel method of laser drilling workpieces, along with novel apparatuses, that allows vibrating workpieces to be drilled precisely.